A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but lists are frequently written down on paper, or maintained electronically. Lists are "most frequently a tool", and "one does not read but only uses a list: one looks up the relevant information in it, but usually does not need to deal with it as a whole".[1]
It has been observed that, with a few exceptions, "the scholarship on lists remains fragmented".[1] David Wallechinsky, a co-author of The Book of Lists, described the attraction of lists as being "because we live in an era of overstimulation, especially in terms of information, and lists help us in organizing what is otherwise overwhelming".[2]
While many lists have practical purposes, such as memorializing needed household items, lists are also created purely for entertainment, such as lists put out by various music venues of the "best bands" or "best songs" of a certain era. Such lists may be based on objective factors such as record sales and awards received, or may be generated entirely from the subjective opinion of the writer of the list.[3] Musicologist David V. Moskowitz notes:
There are now top 100 or top 10 lists of a great variety within the music industry and its associated media. Rolling Stone issues top 100 lists of albums, songs, guitarists, and bass players. Guitar Player and Bass Player magazines contain similar lists as do other types of music magazines. This type of "best of" list... is based on a degree of opinion. Certainly, each "best of" list is based in some type of more scientific method than simple opinion, but this varies from list to list . Other "best of" lists are even more subjective, essentially coming down to a nonscientific approach to a single person's opinion. Lists of this sort still appear in mainstream media, such as Billboard magazine's "Top 30 Breakup Songs".[3]
The practice of ordering a list evaluating things so that better items on the list are ahead of less good items is called ranking. Lists created for the purpose of ranking a subset of an indefinite population (such as the top 100 of the thousands of bands that have performed in a given genre) are almost always presented as round numbers. Studies have determined that a list of items falling within a round number has a substantial psychological impact, such that "the difference between items ranked No. 10 and No. 11 feels enormous and significant, even if it's actually quite minimal or unknown".[4] The same list may serve different purposes for different people. A list of currently popular songs may provide the average person with suggestions for music that they may want to sample, but to a record company executive, the same list would indicate trends regarding the kinds of artists to sign to maximize future profits.
Lists may be organized by a number of different principles. For example, a shopping list or a list of places to visit while vacationing might each be organized by priority (with the most important or most desired items at the top and least important or least desired at the bottom), or by proximity, so that following the list will take the shopper or vacationer on the most efficient route.